apathetic • assured • balanced • calm • collected • composed • confident • constant • controlled • cool • coolheaded • dependable • detached • dispassionate • dull • enduring • equable • even • even-tempered • faithful • faithworthy • fast • fiducial • firm • firm as Gibraltar • fixed • flat • immutable • impassive • imperturbable • indifferent • in equilibrium • inexcitable • invincible • levelheaded • nonchalant • orderly • patient • peaceful • placid • poised • predictable • quiescent • quiet • reliable • secure • self-controlled • self-possessed • sensible • serene • smooth • sober • solid • sound • stable • staunch • steadfast • steady • still • Stoic • stolid • substantial • sure • tranquil • true • undisturbed • unemotional • unfailing • unfaltering • unflappable • unflinching • unmoved • unnervous • unperturbed • unruffled • unshakable • unwavering • well-balanced • well-founded • without nerves